Biological studies in space environment have increasingly received special attention from researchers. There are scientific reports showing that changes in gravity as well as changes in the activity of Earth's magnetic field may interfere in living organism development. Hypergravity is one of these changes and can be defined as the increase of weight caused by either the enhancement of the mass of a given body or the acceleration of it (simulated hypergravity condition). It can be seen during launch and re-entry of a spacecraft in the Earth's atmosphere.
On Earth, gravity is present during plant evolution, being used by them to regulate their growth and development (Soga, 2004). Nowadays, two hypotheses try to explain the mechanism of gravity perception in plants. Starch-statolith hypothesis states that dense bodies of starch called amyloplasts, found in root cells, act as a gravity sensor for plants (Kiss et al, 1996; Kiss et al., 1998; Fitzelle, 2001; Aubay-Centis, 2003; Kiss et al., 1999). On the other hand, protoplast pressure hypothesis, by observing genetically modified plants with few amyloplasts, asserts that gravity perception is caused by the weight of root cell content (Caspar, 1989; Guisinger, 1999; MacCleery and Kiss, 1999 Soga et al., 2004; Soga et al., 2005). However, until now, most data referring to gravity influence in plant physiology and morphology have been obtained from plants subject to changes in gravitational vector orientation (Aubay-Centis, 2003). For this purpose, experiments in space provide microgravity conditions, while experiments based on centrifuges provide hypergravity simulated conditions (Soga, 1999).
Experiments under simulated hypergravity can represent the mechanisms involved in animals or plants, in tissues or cells in response to the increase in the gravitational force (van Loon et al., 1993). In the same way, it is possible to create on Earth, by using human centrifuges, a hypergravity environment similar to those generally found in space missions or during an abrupt maneuver of a high performance aircraft. In plants, hypergravity produced by centrifugation is used to analyze the responses of plant seeding to gravity stimulus (Hoson, 2002), although this technique has been employed in the separation of cell components, but only as a primary stimulus (Russomano et al., 2007). Gravitational forces greater than 1G have been useful for studying gravity role in plant growth (Kasahara et al., 1995). Experiments carried out by Hoson (2002) showed that hypergravity produced by centrifugation increased cell wall stiffness due to gravitational force resistance (Soga et al., 1999; Soga, 2004; Hoson et al., 2002). In the same way, it was noticed growth inhibition of elongation in mustard epicotyles (Waitron and Brett, 1990), radish and cucumber hypocotyles (Kasahara et al., 1990), cress hypocotyles (Hoson et al, 1996), azuki bean hypocotyles (Soga et al., 1999), corn coleoptiles and mesocotyls (Soga et al, 2003) and A. thaliana inflorescence stems (Tamaoki et al., 2006) in response to hypergravity. These results suggest that growth inhibition is due to the reduction of cell wall mechanical extensibility (Soga et al., 1999; Hoson et al., 2002; Soga et al., 2003; Soga et al., 2004).
However, morphological experiments carried out by the present inventors showed that arugula seeds germinate faster when exposed to simulated hypergravity. Such results are amazing considering the State of the Art and constitute the starting point to the present invention development.
Scientific and patent literatures regarding publications that are only partially related to the subject of the present invention, however, do not anticipate or suggest, even indirectly, any of the objects of the present invention.
The article entitled “Simulated microgravity and hypergravity attenuate heart tissue development in explant culture” reports the study about hypergravity influence on heart tissue morphogenesis.
U.S. Pat. No. 6,008,009, owned by Universities Research Association and entitled “Centrifuge-operated specimen staining method and apparatus” describes a method and an apparatus of preselected staining where the liquid stained reagents are applied and removed from the staining chamber.
International patent application WO 00/30718, filed by Arthur Kreitenberg and entitled “Exercise apparatus involving centrifugal forces”, describes an exercise apparatus involving centrifugal forces where centrifugal acceleration and Earth gravitational acceleration are summed.
European document EP1030554, owned by Oceaneering International, Inc. and entitled “Method and apparatus for cytoplasmic loading using an impact-mediated procedure” describes a method and an apparatus for the introduction of macromolecules into the cytoplasm of living cells by an impact-mediated procedure that compresses cells with a predetermined number of solid particles in a blast of propellant gas. This procedure can be changed by gravitational conditions and is preferably carried out under hypergravity conditions.
U.S. Pat. No. 3,882,634, by NASA, describes a rotary plant growth accelerating apparatus based on rotation and translation motions about horizontal axes in order to administer nutrients to plants during rotation. Horizontal planetary path reduces gravity effects, that is, it simulates microgravity effects, accelerating plant growth.
U.S. Pat. No. 3,911,619, by Gravi-Mechanics Co., describes an apparatus for seed sprouting also based on rotation motions about horizontal axes. Horizontal planetary path reduces gravity effects, accelerating seed sprouting, and avoiding problems associated to gravity.
U.S. Pat. No. 3,973,353, by Gravi-Mechanics Co., describes a different apparatus to accelerate plant growth based on the application of rotation and translation motions about horizontal axes in order to administer nutrients to plants during rotation. Horizontal planetary path reduces gravity effects, accelerating plant growth.
Results obtained by the present invention system and process are amazing from scientific and patent literature point of view.